The Ultimate Coral Reef Quiz

For an underwater tourist, whether in a wetsuit or in front of a TV, a major attraction is a coral reef, an amazing ecosystem inhabited by myriad colorful marine creatures. Unfortunately, coral reefs are in danger of disappearing unless immediate steps are taken to preserve this natural wonder. Take this quiz to learn more about what needs to be done.

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Question 1 of 20

What is a coral reef?

It is a fossilized remnant of rainforests that were once above the water.

It is a foundation of stone with different types of marine growth covering it.

It is made from stony corals and discharged limestone skeletons.

Coral reefs are made mainly from stony corals and are supported by the limestone skeletons they discharge.

Question 2 of 20

How long will it be until an estimated 70 percent of coral reefs disappear?

20 years

40 years

It is estimated that this will happen within 40 years.

60 years

Question 3 of 20

Does a coral reef contribute to the environment?

It buffets the coastal areas from storms and powerful waves.

The reef buffets coastal regions from powerful waves and storms.

It benefits the tourist trade.

They protect smaller fish from sharks and other predators.

Question 4 of 20

How big is a single coral?

15 millimeters

10 millimeters

3 millimeters

It is only 3 millimeters long.

Question 5 of 20

What is a polyp?

a protrusion from the reef

a single coral

A polyp is an individual coral

digestive gland of the coral

Question 6 of 20

Is the coral a plant?

It's a living creature.

The coral, although it is fixed to one spot, is a living creature.

It is a sophisticated fish-eating plant.

It defies precise definition because of its unique nature.

Question 7 of 20

What does sessile mean?

It's a creature that lies in wait for prey.

It is an asexual creature.

It means fixed in place.

The term comes from the Latin for "sitting" and means without a stalk, attached at the base; in other words fixed in place. It usually refers to plants but also to corals, barnacles and mussels.

Question 8 of 20

Why did scientists originally think corals were plants?

They had never seen a living creature attached to a substratum.

The tentacles of the coral look like tree branches.

When branching corals spread out their tentacles, they resemble trees with branches.

There was no evidence of a breathing mechanism necessary to sustain life.

Question 9 of 20

What is common to the jellyfish, sea anemone and the coral?

carnivorous

They are all related and are carnivorous.

all are protected species

all exist exclusively in tropical waters

Question 10 of 20

Since it cannot move from place to place, how does the coral hunt for prey?

The coral emits secretions that attract marine life which it swallows when in range.

The tentacles send out an electric charge paralyzing small fish.

Its tentacles wait until something small and tasty brushes past.

It is a passive hunter, capturing small fish and other marine life that happens to encounter its tentacles waving gently in the current.

Question 11 of 20

Why could you consider a coral a half-plant?

Algae living in he coral's cell walls provide products the coral turns into nutrients.

There are algae living in the cell walls supplying it with byproducts of photosynthesis, which the coral turns into proteins, fats and carbohydrates.

The coral is implanted in the reef.

The tentacles are identical to parts of certain plants that entrap insects.

Question 12 of 20

What do algae gain from coral?

The algae feed on scraps of undigested fish bones.

The coral supplies carbon, nitrates and phosphates.

The coral offers shelter and provides the algae with carbon, nitrates and phosphates they need.

The algae feed on plant growths that irritate the coral.

Question 13 of 20

What is this useful arrangement known as?

dependency

mutually assured destruction

symbiosis

This mutually beneficent arrangement is known as symbiosis.

Question 14 of 20

What is the substance the polyps secrete?

calcium carbonate

They secrete calcium carbonate or limestone.

phosphate

sodium chloride

Question 15 of 20

To what use is this substance put?

provides toxins for the tentacles

food for other marine life

a protective chamber or shell

The limestone creates a protective skeleton and a hollow chamber into which the polyps retreat in time of danger.

Question 16 of 20

How many polyps can be found in a single branching coral?

hundreds

thousands

A single branching coral can have thousands of individual polyps.

tens of thousands

Question 17 of 20

When polyps join together into a colony what happens to them?

Each polyp continues to operate individually from a common location.

They form larger working groups competing with the other groups.

They all work together as a single organism.

The whole colony operates as a single organism.

Question 18 of 20

Do polyps reproduce?

by producing identical clones (asexually)

by sending out eggs or sperm (sexually)

by dividing thereby producing identical clones (asexually) and by sending out eggs or sperm (sexually)

Polyps reproduce both by dividing thereby producing identical clones (asexually) or by sending out eggs or sperm (sexually).

Question 19 of 20

How is a new colony formed?

Strong underwater currents cause corals to break away and drift to a new location.

Newly created polyps settle downwards until they reach a hard surface.

New coral polyps sink downwards until they reach a hard substrate to which they can become attached. They can join an existing colony or reef or begin a new project.

Large fish break off pieces of coral which they dump when can't digest it.